I've been noticing this behavior out of my GPS and I want to figure out how to eliminate it.

In my car hook up to the lighter getting 14v I can easily get 10-15ft EPE. Once I switch to batter power at 5.5v that drops significantly. Then if it is cold out I can get to no GPS coverage.

Is this just because I dropped form 14v to 5v of power? Can I solve this by picking up two 9.6v tyco r/c batteries and powering the GPS III+ off that. I read in the manul the external plug can handle 10-32 volts so that should be fine.

Edit: I went out and did more experimenting. I think it;s the antenna that went bad.

Ok, here's what I did. I didn't warm the car up. I went to a local huge parking lot so I have alot of sky I can see. I kept my car window open so it would be cold in the car too. I don't have a car mount for my gps. I normall wedge it up betweent he glass and the dash. So I did my normal setup with the gps plugged to the car. 14.3v the gps was reading. I turned it on, picked up about 6 sats and the bars were about 2/3rd to 4/5th full. I was getting 17ft EPE. I pulled the GPS away fromt he window a bit. THe bars dropped to about half but still around 17ft EPE. Keeping the GPS plugged intot he car I took the GPS outside. Bars dropped to less than 1/3rd EPE dropped to about 25ft. Took the GPS off car power and most of the bars dropped completely off adn I got poor gps covereage.

Hmmm. Power is part of it but I think my antenna has gone bad. I can only come up with a couple of ideas on why this is happening. 1) my antenna lost a contact somewhere and when I wedge it up to the glass it reconnects the contacts. This is supported by the fact that when I pull the gps away from the window slightly the bars go down slightly. 2) Inside my car I get better GPS radio waves somehow. The difference between outside and inside the car support this theory.

Now, factors that still could be affecting this. Power and cold. Since it was cold through out I cant eliminate cold had something to do with it. I might have to go experiment in a warmed up car sometime.

But I have a strong suspision my antenaa is faulty now. Which is highly possible. The outside plastic casing broke off. I now have electrical tape around the antenna to protect it from water.

My next step I think is to borrow my friends antenna and put it on my gps.

OK, I really need someone else witha garmin GPS series to verify what's going on. I "think" it might be the antenna. My external isn;t working either, I haven't picked up a new battery for it as that might be the problem with the external. Too many variables on what could be wrong, I need to start eliminated some of them.

Well, I won't be caching for awhile. I took apart my gps again. I noticed the circuit board etxhing for the antenna was cracked which definately explains why it has been doing what it has been doing. I tries to fix it but now my gps won't boot. sigh. Now I just need a job so I can replace it with a V